/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.metrics.metricsets.logback;

import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.LoggerContextListener;
import org.apache.iotdb.metrics.AbstractMetricService;
import org.apache.iotdb.metrics.metricsets.IMetricSet;
import org.apache.iotdb.metrics.utils.MetricType;
import org.slf4j.LoggerFactory;

import java.util.HashMap;
import java.util.Map;

/**
 * This file is modified from io.micrometer.core.instrument.binder.logging.LogbackMetrics
 */
public class LogbackMetrics implements IMetricSet {
    private static final org.slf4j.Logger logger = LoggerFactory.getLogger(LogbackMetrics.class);
    static ThreadLocal<Boolean> ignoreMetrics = new ThreadLocal<>();
    private final LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
    private final Map<AbstractMetricService, MetricsTurboFilter> metricsTurboFilters =
            new HashMap<>();

    public LogbackMetrics() {
        loggerContext.addListener(
                new LoggerContextListener() {
                    @Override
                    public boolean isResetResistant() {
                        return true;
                    }

                    @Override
                    public void onReset(LoggerContext context) {
                        // re-add turbo filter because reset clears the turbo filter list
                        synchronized (metricsTurboFilters) {
                            for (MetricsTurboFilter addMetricsTurboFilter : metricsTurboFilters.values()) {
                                loggerContext.addTurboFilter(addMetricsTurboFilter);
                            }
                        }
                    }

                    @Override
                    public void onStart(LoggerContext context) {
                        // no-op
                    }

                    @Override
                    public void onStop(LoggerContext context) {
                        // no-op
                    }

                    @Override
                    public void onLevelChange(Logger logger, Level level) {
                        // no-op
                    }
                });
    }

    @Override
    public void bindTo(AbstractMetricService metricService) {
        MetricsTurboFilter filter = new MetricsTurboFilter(metricService);
        synchronized (metricsTurboFilters) {
            metricsTurboFilters.put(metricService, filter);
            loggerContext.addTurboFilter(filter);
        }
    }

    @Override
    public void unbindFrom(AbstractMetricService metricService) {
        try {
            synchronized (metricsTurboFilters) {
                for (MetricsTurboFilter addMetricsTurboFilter : metricsTurboFilters.values()) {
                    loggerContext.getTurboFilterList().remove(addMetricsTurboFilter);
                }
                metricService.remove(MetricType.COUNTER, "logback_events", "level", "error");
                metricService.remove(MetricType.COUNTER, "logback_events", "level", "warn");
                metricService.remove(MetricType.COUNTER, "logback_events", "level", "info");
                metricService.remove(MetricType.COUNTER, "logback_events", "level", "debug");
                metricService.remove(MetricType.COUNTER, "logback_events", "level", "trace");
            }
        } catch (Exception e) {
            logger.error("Failed to remove LogBackMetrics.");
        }
    }
}
